Rope structure



im, 8, @924o H. G. METCALF ROPE STRUCTURE Filed June` 18, 1923 Patenteddan.; S, i924,

naires? santasN Ld'lt FATN? @FFQM Hannan e. Maronti?, or AUBURN, nnwYoan.

RCPE STRICTURE.

Application filed June 18, 1923. Serial No,v 646,183.

v drawings, forming part of this specification.

This invention relates to improvements in cordage, particularlyapplicable to rope structures generally, that is to say, thosestructures made up of three, four, six, `or nine strands or readiesassembled either in regular laid rope, or in cable-laidrope, the objectof the invention being to increase the strength of the rope as well asthe lasting qualities in the performance of work requiring constantbending or liexure, as well as in Work wherein the rope is subjected toabrasion.

In the production of rope embodying the present invention certaindevelopments made in connection .with the arrangement of the fibersinthe rope structure are utilized with the object first of simplifyingand reducing the cost of manufacture and, secondly, of not onlyincreasing the strength of the rope, under tension, but also increasingits flexibility and internal wear resisting qualities.

In accordance with the present invention, the strands or readies fromwhich'rthe rope structure is built up are each composedv of an internalportion wherein the -main strength .of the rope to resist tensionstrains is found, and an external portion designed 46 to resist wear andabrasion,'but, of course, to a certain extent also adding to the tensilestrength o'f the rope. rll`he internal portion of each strand or readyis formed directly of sliver fibers and the fibers occupy substantiallyparallel relation to each other and are twisted only to a slight degree,usually conforming to the forming twist of the strand or ready, but thedegree 50, of twist may be varied in accordance with known practice.Buried within the central sliver ber portion of the strand or ready andpreferably axially thereof, there is a yarn or a ply yarn which yarn orply yarn is lthoroughly covered and impreg. nated with graphite orgrease or waterproofing material having water repellant and lubricatingqualities. Around the central portion of the rope strand or ready soformed of sliver fiber, there 'is wound in parallelism a coveringcomposed of yarns or ply yarns and there may be one or a plurality oflayers vof such yarns or ply yarns to Agive the desired abrasiveresisting qualities to the rope, as well as to exert a ,binding actionon the central portion, in order to increase the strength of the rope byeliminating any tendencyof the `fibers to slip and separate from eachotherwhen subjected to severe tensionstrains, especially where the twistimparted to the sliver center is not in itself suiii'cientto accomplishthis result. In'some instances each of a series of slivers hasincorporated in it a single yarn or a ply yarn which is thoroughlycovered and impregnated with the lubricating and water .resistingmaterial or the lubricating yarn'may be at the center v and surroundedby the series of slivers, but in all cases it is embedded in arelatively large mass of sliver fiber. l

In order that the use of the terms sliver,

"yarn, and ply yarn may be understood herein, such terms may be definedas follows: A sliver is a relatively large body of fibers which havebeen straightened and doubled the requisite number of times to insureuniformity and parallelism of they fibers, and this sliver fiber is inthe rope structure, twisted-onlyisutficiently to hold the fiberstogether and to prevent them from separating readily by being pulledapart. In some instances this sliver may have its individual fibers heldtogether' inA part or in whole by thepenclosing sheath of yarn or plyyarn. y A single yarn is a relatively small body of libers suitablydoubled and straightened and twisted or spunv into a.. structure, whichhas the relatively hard 'i twisted characteristics of a thread' or cord.A ply yarn is a plurality of single yarns which are twisted together andmaintain their form or the characteristics of a cord formed of aplurality of single threads or ,i 6,5 stretched or elongation of theropatakes lin the drawings: Figure l represents a section of a threestrand rope, one strand at the end being opened out to illustrate theinternal structure;

Fig. 2 is a cross section of the rope illustrated in Fig. l; and

Fig. 3 is a cross section illustrating a modification wherein aplurality of slivers constitute the center portion of the rope and ineach sliver there is embedded a lubricant impregnated single yarn or plyyarn.

Referring particularly to Figs. l and 2, the letter A indicates the.enveloping sheath for each of the strands or readies, this envelopingsheath being formed of a single or plural layers of yarns a. These yarnsmay be, as ordinarily, either 'single or ply yarns, but are preferablysingle yarns, inasmuch as it is desirable to have the fibers of theyarns twisted together only to that.. degree which is necessary toconstitute a good wearing or abrasion resisting cover or sheath, and atthe same time to leave the fibers as free as possible from all tendencyto cut each other or to shear under the action of bending or tensionstresses. The center portion of each strand or ready is formed of sliverber, a sliver or series of sliverspreferably, though not necessarily,four or more in number, as indicated at B, and these slivers have atwist imparted to them, which, in the preferred structure, substantiallycorresponds to the twist imparted to the whole ready or strand in layingthe sheath or cover thereon,

in the rope machine, to which machine the sliver is preferably fed in asubstantially untwisted condition. Embedded in the sliver fiber centerso formed is the impregnated yarn or ply yarn C which is illustrated inthev drawings as a black center, indicating that it is impregnated withgraphite, grease or other lubricating and water-proong compound.

Insteadof incorporating the lubricating yarn or ply yarn B- in thecenter or along the axial line of each strand or ready, each of theslivers incorporated in the center may have an impregnated yarn Eincorporated therein, as indicated -in Fig. 3 of the drawing, therebeing thus incorporated ineach ready a plurality-of impregnated yarnsseparated from each otherbyjthe fiber constituting the adjacent portionsof the slivers from which the center is formed, thus distributing thelubricatingand waterLrepellant mal'terialthroughout a greater area ofthe fiber.l

The impregnated yarns so incorporated in the slivers are twisted to agreater degree than the slivers themselves, and consequently present agreater length Aof ber in a'given length of rope. .linother words, thisyarn belng a hard Atwisted portion of the structure will .be capableoflengthening out when By locatingthe lubricating impregnated v' yarn in avsurrounding body of soft fibers, so to speak, it is found that thedistribution of the lubricant is not only such that it is most effectivewhere lubrication is secured, but in use, the lubricant distributesitself to the surrounding fibers and after a brief interval of use thecenter of the rope has lubricating qualities imparted there-to 'to agreater or less degree throughout, and from the beginning the rope as awhole is flexible to a degree which is practically impossible of'attainment in ropes heretofore produced and which were made of yarns inthe ordinary way.

An additional advantage has become inanifest in ropes of this character,due to the fact that while the fibers constituting the rrope areeiectually clamped together, so to speak, as to prevent slipping withrelation to eachother, their entire tensile strength becomes availablewithout that tendency to shear and cut, as in all liard laid ropesheretofore madewith the result that the tensile strength of a rope madein-accordance Awith the present invention, aswell as its capacity forresistingbending stresses and constant usage in bending or externalabrasion are greatly increased.

It will be understood, of course, that the 'this art.

-`Whatlclaim is: Y

1. A rope structure comprising a plurality ofstrands or readies laidtogether in twisted relation tovform the finished rope, each of saidstrands comprising a twisted yarn or ply yarn impregnated with alubricating or water repellant substance and embedded in and surroundedby a relatively large body of sliver fibers twisted to a degree lessthan that of the impregnated yarn to form a relatively soft center, thewhole being surrounded by yarns each twisted to a greater degree thanthe slivers, said yarns being spirally laid about the center and withadjacent yarns in contactwith each other to form an enveloping sheath.

2; A rope Structure comprising a plurality of strands or readies laidtogether in twisted relation to form theinished rope, each of saidStrands comprising an envelope 4or lllilO lill@ las ' laid about acenter with adjacent yarns' `1n contact, a relativel large sliver fiber'center twisted to substantlally conform to the spiralA 5 lay of theenvelopin yarns and a yarn or ly yarn of twisted bers impregnated withubricantv embedded in the sliver center.

3. A rope structure comprising a plurality of strands or' readies laidtogether in twisted l0 relation'to form the finished rope, each of saidstrands comprising laid about vaA center with adjacent 4yarns 1n aplurality of slivers twisted to conform to the spiral lay of theenveloping yarns and a yarn or sly arn of twisted fibers impre nated witv1u ricant'and located centra y between the slivers.

v an envelope or sheath of individually twisted yarns spirally HAROLD G.METCALF.

contact, 'a relatively large center formed of j l5

